620-71-3Relevant academic research and scientific papers
Activity patterns of metal oxide catalysts in the synthesis of N-phenylpropionamide from propanoic acid and aniline
Arena, Francesco,Deiana, Chiara,Lombardo, Agata F.,Ivanchenko, Pavlo,Sakhno, Yuriy,Trunfio, Giuseppe,Martra, Gianmario
, p. 1911 - 1918 (2015)
The reactivities of various commercial and lab-made oxide samples (e.g., γ-Al2O3, CeO2, ZrO2 and TiO2) in the heterogeneous catalytic synthesis of N-phenylpropionamide (T, 383 K) from aniline and propanoic acid have been investigated. All the materials studied drive the direct synthesis of the amide to an extent depending on both the chemical and structural properties. A 0th-order kinetic dependence on the substrate concentrations suggests that the reaction proceeds via a Langmuir-Hinshelwood (L-H) pathway under kinetic control of the adsorption-desorption steps (the rate determining step, r.d.s.). The comparative analysis of the activity data on the basis of the relative surface specific kinetic constant discloses a superior surface reactivity of TiO2, CeO2 and ZrO2 over the γ-Al2O3 system, and also highlights marked differences in the catalytic functionality of the titania samples. IR spectroscopic studies of the carboxylic acids and amine adsorption and interaction patterns show the formation of the bidentate, bridging, and unidentate carboxylate intermediates accounting for the different amidation functionalities of the studied materials.
Asymmetric Markovnikov Hydroaminocarbonylation of Alkenes Enabled by Palladium-Monodentate Phosphoramidite Catalysis
Yao, Ya-Hong,Yang, Hui-Yi,Chen, Ming,Wu, Fei,Xu, Xing-Xing,Guan, Zheng-Hui
supporting information, p. 85 - 91 (2021/01/12)
A palladium-catalyzed asymmetric Markovnikov hydroaminocarbonylation of alkenes with anilines has been developed for the atom-economical synthesis of 2-substituted propanamides bearing an α-stereocenter. A novel phosphoramidite ligand L16 was discovered which exhibited very high reactivity and selectivity in the reaction. This asymmetric Markovnikov hydroaminocarbonylation employs readily available starting materials and tolerates a wide range of functional groups, thus providing a facile and straightforward method for the regio- and enantioselective synthesis of 2-substituted propanamides under ambient conditions. Mechanistic studies revealed that the reaction proceeds through a palladium hydride pathway.
Photo-on-Demand Synthesis of Vilsmeier Reagents with Chloroform and Their Applications to One-Pot Organic Syntheses
Liang, Fengying,Eda, Kazuo,Okazoe, Takashi,Wada, Akihiro,Mori, Nobuaki,Konishi, Katsuhiko,Tsuda, Akihiko
, p. 6504 - 6517 (2021/05/06)
The Vilsmeier reagent (VR), first reported a century ago, is a versatile reagent in a variety of organic reactions. It is used extensively in formylation reactions. However, the synthesis of VR generally requires highly toxic and corrosive reagents such as POCl3, SOCl2, or COCl2. In this study, we found that VR is readily obtained from a CHCl3 solution containing N,N-dimethylformamide or N,N-dimethylacetamide upon photo-irradiation under O2 bubbling. The corresponding Vilsmeier reagents were obtained in high yields with the generation of gaseous HCl and CO2 as byproducts to allow their isolations as crystalline solid products amenable to analysis by X-ray crystallography. With the advantage of using CHCl3, which bifunctionally serves as a reactant and a solvent, this photo-on-demand VR synthesis is available for one-pot syntheses of aldehydes, acid chlorides, formates, ketones, esters, and amides.
Visible-Light Carbon Nitride-Catalyzed Aerobic Cyclization of Thiobenzanilides under Ambient Air Conditions
Bai, Jin,Yan, Sijia,Zhang, Zhuxia,Guo, Zhen,Zhou, Cong-Ying
supporting information, p. 4843 - 4848 (2021/06/28)
A metal-free heterogeneous photocatalysis has been developed for the synthesis of benzothiazoles via intramolecular C-H functionalization/C-S bond formation of thiobenzanilides by inexpensive graphitic carbon nitride (g-C3N4) under visible-light irradiation. This reaction provides access to a broad range of 2-substituted benzothiazoles in high yields under an air atmosphere at room temperature without addition of a strong base or organic oxidizing reagents. In addition, the catalyst was found to be stable and reusable after five reaction cycles.
Manganese(I) Catalyzed α-Alkenylation of Amides Using Alcohols with Liberation of Hydrogen and Water
Pandia, Biplab Keshari,Gunanathan, Chidambaram
, p. 9994 - 10005 (2021/07/31)
Herein, unprecedented manganese-catalyzed direct α-alkenylation of amides using alcohols is reported. Aryl amides are reacted with diverse primary alcohols, which provided the α,β-unsaturated amides in moderate to good yields with excellent selectivity. Mechanistic studies indicate that Mn(I) catalyst oxidizes the alcohols to their corresponding aldehydes and also plays an important role in efficient C═C bond formation through aldol condensation. This selective olefination is facilitated by metal-ligand cooperation by the aromatization-dearomatization process operating in the catalytic system. Biorenewable alcohols are used as alkenylation reagents for the challenging α-alkenylation of amides with the highly abundant base metal manganese as a catalyst, which results in water and dihydrogen as the only byproduct, making this catalytic transformation attractive, sustainable, and environmentally benign.
Photocatalyzed Triplet Sensitization of Oximes Using Visible Light Provides a Route to Nonclassical Beckmann Rearrangement Products
Rovis, Tomislav,Zhang, Xiao
supporting information, p. 21211 - 21217 (2021/12/27)
Oximes are valuable synthetic intermediates for the preparation of a variety of functional groups. To date, the stereoselective synthesis of oximes remains a major challenge, as most current synthetic methods either provide mixtures of E and Z isomers or furnish the thermodynamically preferred E isomer. Herein we report a mild and general method to achieve Z isomers of aryl oximes by photoisomerization of oximes via visible-light-mediated energy transfer (EnT) catalysis. Facile access to (Z)-oximes provides opportunities to achieve regio- and chemoselectivity complementary to those of widely used transformations employing oxime starting materials. We show an enhanced one-pot protocol for photocatalyzed oxime isomerization and subsequent Beckmann rearrangement that enables novel reactivity with alkyl groups migrating preferentially over aryl groups, reversing the regioselectivity of the traditional Beckmann reaction. Chemodivergent N- or O- cyclizations of alkenyl oximes are also demonstrated, leading to nitrones or cyclic oxime ethers, respectively.
Palladium-Catalyzed Direct Dicarbonylation of Amines with Ethylene to Imides
Kuai, Chang-Sheng,Wang, Le-Cheng,Wu, Xiao-Feng,Xu, Jian-Xing
, (2022/01/04)
The selective and effective conversion of low-cost and simple bulk chemicals into high value-added products through catalytic strategy has a wide range of practical significance. Here, a palladium-catalyzed method for the direct and efficient dicarbonylation of amines with basic industrial feedstock ethylene to imide has been developed. Moderate to excellent yields of the desired imides can be produced from readily available amines in a straightforward manner.
Carboxylic Acid Deoxyfluorination and One-Pot Amide Bond Formation Using Pentafluoropyridine (PFP)
Brittain, William D. G.,Cobb, Steven L.
supporting information, p. 5793 - 5798 (2021/08/01)
This work describes the application of pentafluoropyridine (PFP), a cheap commercially available reagent, in the deoxyfluorination of carboxylic acids to acyl fluorides. The acyl fluorides can be formed from a range of acids under mild conditions. We also demonstrate that PFP can be utilized in a one-pot amide bond formation via in situ generation of acyl fluorides. This one-pot deoxyfluorination amide bond-forming reaction gives ready access to amides in yields of ≤94%.
Visible-light induced one-pot hydrogenation and amidation of nitroaromatics with carboxylic acids over 2D MXene-derived Pt/N-TiO2/Ti3C2
Jiang, Heyan,Hu, Zujie,Gan, Chuan,Sun, Bin,Kong, Shuzhen,Bian, Fengxia
, (2021/03/03)
Pt nanoparticles supported on N doped titanium dioxide/titanium carbide (MXene) heterojunctions were employed as photocatalysts for the tandem reactions between aromatic nitro compounds and carboxylic acids to produce amide products. The 3%Pt/N-TiO2/Ti3C2 heterojunction was prepared by in situ grew TiO2 on Ti3C2 nanosheets and then N doped TiO2 with melamine, Pt nanoparticles with 3.3 nm mean diameter well dispersed on N-TiO2/Ti3C2. 3%Pt/N-TiO2/Ti3C2 had excellent amidation activity and chemoselectivity under visible-light irradiation. The elevated catalytic performance of 3%Pt/N-TiO2/Ti3C2 was owing to the improvement in photogenerated electron and hole separation efficiency through charge short-range directional transmission caused by the intimate contact between the TiO2 and the conductive Ti3C2. This direct hydrogenation along with amidation between nitroaromatics and carboxylic acids own actual merits in the amides produce with no harmful byproducts. In situ DRIFTS spectra verified that the amidation activation with visible light irradiation at 25 °C was much faster than heating.
Method for catalyzing one-pot hydrogenation and amidation of nitroaromatic hydrocarbon and carboxylic acid by visible light
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Paragraph 0028, (2021/06/09)
The invention discloses a method for catalyzing one-pot hydrogenation and amidation reaction of nitroaromatic hydrocarbon and carboxylic acid by visible light. The method comprises the following steps: preparing Pt nanoparticles uniformly dispersed on an N-doped titanium dioxide/titanium carbide (MXene) heterojunction as a photocatalyst (3% Pt/N-TiO2/Ti3C2), and applying the catalyst to a cascade reaction of an aromatic nitro compound and carboxylic acid to prepare an amide product. The 3% Pt/N-TiO2/Ti3C2 has excellent tandem hydrogenation and amidation activity and chemical selectivity of an aromatic nitro compound and carboxylic acid under the irradiation of visible light. The excellent catalytic performance of 3% Pt/N-TiO2/Ti3C2 is attributed to the close contact of TiO2 and conductive Ti3C2, and the separation efficiency of photo-induced electrons and holes is improved through charge short-range directional transmission. The preparation method of the catalyst is simple and easy to operate, the catalyst can be used for photocatalytic efficient one-pot hydrogenation and amidation reactions, the reaction conditions are mild, and the catalyst is easy to recycle.
